Status Codes and Error Responses

Either when an error occurs or when a response is successful, the response header contains an HTTP code, and the response body usually contains:

The HTTP response code
The message accompanying the HTTP response code
The field or object where the error occurred (if the response returns information about an error)

HTTP response code	Description
200	“OK” success code, for GET, HEAD, and some PATCH requests.
201	“Created” success code, for POST requests and some PATCH requests.
204	“No Content” success code, for DELETE requests and some PATCH requests.
300	The value returned when an external ID exists in more than one record. The response body contains the list of matching records.
304	The request content has not changed since a specified date and time. The date and time is provided in a `If-Modified-Since` header. See Get Object Metadata Changes for an example.
400	The request couldn’t be understood, usually because the JSON or XML body contains an error.
401	The session ID or OAuth token used has expired or is invalid. The response body contains the `message` and `errorCode`.
403	The request has been refused. Verify that the logged-in user has appropriate permissions. If the error code is REQUEST_LIMIT_EXCEEDED, you’ve exceeded API request limits in your org.
404	The requested resource couldn’t be found. Check the URI for errors, and verify that there are no sharing issues.
405	The method specified in the Request-Line isn’t allowed for the resource specified in the URI.
409	The request could not be completed due to a conflict with the current state of the resource. Check that the API version is compatible with the resource you are requesting.
412	The request was not executed because one or more of the preconditions that the client specified in the request headers was not satisfied. For example, the request includes an `If-Unmodified-Since` header, but the data was modified after the specified date.
414	The length of the URI exceeds the 16,384 byte limit.
415	The entity in the request is in a format that’s not supported by the specified method.
431	The combined length of the URI and headers exceeds the 16,384 byte limit.
500	An error has occurred within Lightning Platform, so the request couldn’t be completed. Contact Salesforce Customer Support.
503	The server is unavailable to handle the request. Typically this occurs if the server is down for maintenance or is currently overloaded.

Incorrect ID example

Using a non-existent ID in a request using JSON or XML (request_body.json or request_body.xml)

1[
2{
3  "fields" : [ "Id" ],
4  "message" : "Account ID: id value of incorrect type: 001900K0001pPuOAAU",
5  "errorCode" : "MALFORMED_ID"
6}
7]

Resource does not exist

Requesting a resource that doesn’t exist, for example, if you try to create a record using a misspelled object name

1[
2{
3  "message" : "The requested resource does not exist",
4  "errorCode" : "NOT_FOUND"
5}
6]

REST API Developer Guide

Status Codes and Error Responses